Question

The moons of Mars, Phobos (Fear) and Deimos (Terror), are very
close to the planet compared to
Earth?s Moon. Their orbital radii are 9,378 km and 23,459 km
respectively. What is the ratio of the
orbital speed, v, of Phobos to that of Deimos?
A) 1.582 B) 3.956 C) 0.3998 D) 0.2528 E) 2.858